Hi Paul..

Took some Images of the rear Beam in the general position I intend to mount.












As you can see the axle line is a bit further back, you can move it forward but would need to modify the tubes arround the rear of the tranny tunnel..

The chassis is resting about correct ride hight so there will be a bit of camber alraeady ( nothing we are not used to on the sierra. ) Although this is with 16" rims

I have still to work out the rest of the rear end support...

I know it's not elegant but I am trying to keep cost down... Pulled from spares cupboard..

TT

nice one rob - cheers, not overly happy about having the mounting pieces sitting below the floor level tho - maybe thats something i will work on while designing the rear ennd of my chassis

cheers m8

this is very similar to the setup i have ended up stuck with. Points i would mention, is that its a bloody heavy subframe! and on mine, i have ended up with excessive camber, and i mean shitloads of it... its gonna go thru tyres fast.

aside from that, it does save a lot of effort.

ya got any pics please joel?

sorry, no camera! i mounted mine a bit further back, with the two donut like things about 3 inches behind the panel behind the seats. only other mounting point is the bolt on the back of the diff. think mine was too low here, hence the shady angles. then just welded brackets directly onto the trailing arms, for the coilovers. it works, but it wont contribute much to handling...

d'oh - i'm sure i'll nock summat up with not much problem

Performance Sierra owners are used to too much camber...

Decambering is possible, with shimming

TT

There is a good diagram on the locost car club site shwoing how to mount the complete sierra rear suspension unit on a book chassis link here

i tried this as my first attempt at irs on my car
i scraped it because the car looked out of proportion and the rear wheels looked to far back
finally as joel says this tube is bloody heavy
if i was to do my back end again and i am not because its took three different designs to get it right ( and delayed me 10 months) i would spend my money on a gts dedion
when you go off book its a whole can of worms
ps have a look at the thread suspension book
cheers dave

Andy:

The Diagram is ok, but does not actualy give any info or dimensions that are a revelation..

In fact it's missing a whole load of dimensions of any use..

Dave:

I am fully aware it's not ideal, but this is a first build "mule" to test ideas on..

The next chassis will be the Mcsorley long'n'wide with dual wishboned rear.. But that's some time off..

TT

take a look at a tiger cat they use the entire rear beam. Also the camber can be removed by fitting camber wedges (rs jigtec used to sell them for £25 a pair). Seem to indicate a 2 degree wedge . someone on here must be able to make these ?

the rh people had this info

http://community.rhocar.org/index.php?showtopic=1197
Rescued attachment post-5-1060635347.jpg

iirc the plans for the sierra torque tube are to suit a 46" wide chassis
ie a plus 4 chassis
and yes lots of the dimentions are missing
have a good luck at a robin hood they do the same kind of thing with the 2b
but watch out the robin hood is a bit wider than 46" i think its about 48/50"wide
cheers dave

If you are happy to go with a semi-trailing arm setup, then surely ditching that boat anchor of a tube and putting brackets directly on the chassis (with suitable reinforcing) is the way to go? Would also mean you can dial out the static camber by placement of the brackets.

The plans are for the book chassis.

I had considered dumping the tube and just using the trailing arms.. This is an idea I may look at further.. The beam does incorporate some cushioning but prehaps this will not be missed on the locost.

It would certainly add more scope for location of the suspension. And the inner mounts are incorporated with the diff carrier so only the outer ones would be required.

TT

when I looked at trying to use the sierra irs, mounting the big front tube mounts to the flat floor would have created a really big ride height.

if you look at pics of the robin hood 2b chassis, you will see they are recessed.

atb

steve

I am tipping that can of Hyper Clean doesnt see too much use around your pace. Same with the broom and shovel!

Hyperclean get's used evertime I am in the garage..

It's in a bit of a state at the moment. Not had any time to tidy up let alone work on the car.. And that garage is packed full...

1x Cosworth 24v
1x dismantled crossflow
1x dohc head
2x 4x4 sump
2x sierra fuel tank
2x Xr4x4 box
2x sierrea beam
3xsierra front diff
1x escort Box
12x alloy wheel + tyre
welder
compressor
crane
tools
8 cans spent oil
6 sets sierra suspension
4 sierra wishbones
4 front driveshafts..
2 steering racks
sierra 4x4 transmission tunnel
r/c plane
Diff

and that's just inside.....

2 vw engines outside
another box.....

etc...

And the Locost is not even supposed to be in the garage....

That's wher the prime project is supposed to be..

TT
]

What hight should the chassis be off the ground?

TT

mines 4 or 5 inches. cant remember!

Ahh,

It's sitting 7" at the back and 6" at the front at the moment..

Camber at the back would be much worse witha 3" drop..

Think I will look at refabricating the mountings into the chassis and dispensing with most of the beam. Seems like a decent compromise.

TT

my highly non std not-a-locost car is approx 8 ins off the ground. It looks ok on a 30's - 40's sports car replica, but would look like a land rover version of a locost if used on a 'book' car




atb

steve

Have a look at Spags "Pievan", a mini van with a mid mounted Rover V8 and using Sierra-esque rear suspension. He has actually fabricated his own trailing arms based on the Sierra items:
http://www.spagweb.com/v8mini/pievan/sub_2.htm

Rest of the site is well worth a browse!

I did something similar, but much more beefy than that.

looks to me like the hubs might tend to fold inwards. Mine was braced with 5mm plate onto 50mm arms

cant say they will ever fail tho - makes the 16mm rose joints look whimpy tho


atb

steve

TT,

Deepest sympathies... I hadn't realised you lived in Boscastle!



Atb,
James

Actualy the lower weather strip on the garage lets in water during heavy rain..

Not quite a torrent like BC though...

TT

Those mini pics are good, once the basic chassis works then I may custom build the arms..

Think I will chop up the spare, spare beam and see what will work..

TT

[Edited on 18/8/04 by twinturbo]

quote:

---

Originally posted by stephen_gusterson
I did something similar, but much more beefy than that.

looks to me like the hubs might tend to fold inwards. Mine was braced with 5mm plate onto 50mm arms

---

Yes, there aint much hight on them, I would expect them to twist a bit.

TT

It looks like I should be able to cut off teh original center mounts, turn tehm upside down. Swap them side to side and weld them to a strenghtend ( doubled ) rear tub tube )

That mounts them slightly further in, and would raise the moutn by about 1-2"

TT

Do you really want that horrible ugly Sierra back end attached to your lovely finished Locost?

Cough up the mere 150quid for GTS' De Dion system and get something you know will handle well and weigh about a quarter the weight.

I know you want to do it cheaply but this part (the handling/suspension setup) is one of the most important things on the car- why skimp/take risks with it?

HTH,

James

Or what about a escort or capri axle for about £50 off of ebay?

quote:

---

Originally posted by James

Cough up the mere 150quid for GTS' De Dion system and get something you know will handle well and weigh about a quarter the weight.

I know you want to do it cheaply but this part (the handling/suspension setup) is one of the most important things on the car- why skimp/take risks with it?

HTH,

James

---

i think james is giving you some very good advise but if you are like me and want to do it all yourself ( to keep the cost down 2 kids etc)
i can send you a sketch of my irs its been drawn up with a lot of help from pete bura with the suspen program and it seems to be working fine
good luck dave

That would be wonderful..

I know 2 things.

1) I don't want a beam axle
B) I want to utilise whatever I can of doner.
3) I like to be different. As many have said the book is only a guide not a definative step by step.

TT

This is how Tiger do it on the Cat....




James